- vsnet-campaign-dn - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-campaign-dn 17582] TCP J00560713+4301406: new large-amplitude outburst, likely a dwarf nova
by Yusuke Tampo 01 Jun '26

01 Jun '26

TCP J00560713+4301406: new large-amplitude outburst, likely a dwarf nova TCP J00560713+4301406 was discovered at 12.2 mag on 2026 06 01.4 UTC. http://www.cbat.eps.harvard.edu/unconf/followups/J00560713+4301406.html ATLAS also detected this outburst on 2026 05 31.6 UTC around 15.5 mag, likely on the rise. There is a possible counterpart at ~3" away; Gaia 375654744699712512 at ~20.36 mag, thus, the outburst amplitude is ~8 mag. Its blue color (BP-RP~0.34 mag) and distance 1049(-400/+1016) pc are consistent with a counterpart being a CV with a low mass-transfer rate. Although the visibility is not great, time-resolved photometry or snap spectroscopy to confirm its nature is encouraged. Best regards, Yusuke -- ---------------------------------------------- South African Astronomical Observatory, Postdoc fellow Yusuke TAMPO / 反保雄介 EMAIL: tampo(a)kusastro.kyoto-u.ac.jp ALT. EMAIL: yusuke(a)saao.ac.za ----------------------------------------------

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[vsnet-campaign-dn 17579] ATLAS26dqo: new WZ Sge-type dwarf nova
by tonny.vanmunster＠gmail.com 19 Apr '26

19 Apr '26

Dear colleagues, ATLAS26dqo (aka TCP J16163603+4452289) was discovered by the ATLAS survey (J. Tonry et al.) on 2026 Mar 31.5 at mag 18.8. The object subsequently reached a peak of mag 14.0. The quiescent counterpart is a 22.8 g mag star, implying an outburst amplitude of ~9 mag. I have completed the analysis of my unfiltered CCD time-series observations of ATLAS26dqo, obtained on 2026 Apr 14/15 (CBA Belgium Observatory), and Apr 15/16 (CBA Extremadura Observatory, Spain). The data were acquired under mostly clear skies with 0.40-m telescopes. Key findings: * Superhump evolution: the Apr 14/15 light curve shows the emergence of Stage A superhumps with an amplitude of 0.07 mag. By Apr 15/16, the system transitioned into fully developed Stage B common superhumps with an amplitude of 0.14 mag. Note that I observed this object on multiple nights before Apr 15/16, but no obvious modulations were seen. * Period analysis: using multiple methods (ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM via Peranso 3.1), I derive a combined superhump period of 0.0608 +/- 0.0004d for the night of Apr 15/16. * Magnitude: the object was measured at mag CV = 15.5 on Apr 15th. Conclusion: The extreme outburst amplitude (almost 9 mag) and the remarkably long delay (~15 days) between initial discovery and the onset of common superhumps strongly confirm that ATLAS26dqo is a new WZ Sge-type dwarf nova. Image calibration and photometry were carried out using Phoranso, which enabled simultaneous photometry of additional variable stars in the same field of view. Continued monitoring is strongly encouraged to study the superhump profile and evolution. I will submit my observations to AAVSO, CBA and VSNET for further analysis. With kind regards, Tonny --- Tonny Vanmunster CBA Belgium Observatory CBA Extremadura Observatory http://www.cbabelgium.co <http://www.cbabelgium.com/> m PERANSO : The Light Curve and Period Analysis Software http://www.peranso.co <http://www.peranso.com/> m PHORANSO: Photometric Reduction and Analysis Software http://www.phoranso.com <http://www.phoranso.com/>

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[vsnet-campaign-dn 17578] ASASSN-26ck: new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 07 Apr '26

07 Apr '26

Dear colleagues, ASASSN-26ck was discovered by the ASAS-SN team on 2026 Mar 26.3 at mag g = 14.6. The quiescent counterpart is a 21.9 g mag star or a ~23.5 mag star, implying an outburst amplitude of ~7 to 9 mag. I have just completed the analysis of my unfiltered CCD time-series observations of ASASSN-26ck, obtained on 2026 Apr 04/05 and 05/06 at CBA Extremadura Observatory, and Apr 06/07 at CBA Belgium Observatory. The CBA Belgium data were acquired under clear skies with a 0.40-m f/10.0 telescope and a QHY-268M CMOS camera. No obvious modulations were seen on the nights of Apr 04/05 and 05/06. However, the Apr 06/07 light curve clearly shows regular superhump modulations with an amplitude of 0.15 mag. A period analysis using ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.1) yields a combined superhump period of 0.0601 +/- 0.0014d. The object was measured at mag CV = 16.1 on Apr 06th. Image calibration and photometry were carried out using the latest release of Phoranso, which enabled simultaneous photometry of additional variable stars in the same field of view. These results establish ASASSN-26ck as a new SU UMa-type dwarf nova. Further follow-up observations are encouraged to refine the superhump period and study its evolution. I will submit my observations to AAVSO, CBA and VSNET for further analysis. With kind regards, Tonny --- Tonny Vanmunster CBA Belgium Observatory CBA Extremadura Observatory http://www.cbabelgium.co <http://www.cbabelgium.com/> m

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[vsnet-campaign-dn 17577] TCP J08460573+1047397: new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 02 Apr '26

02 Apr '26

Dear colleagues, TCP J08460573+1047397 was discovered by the NMW-TexasTech transient survey (K. Sokolovsky et. al.) on 2026 Mar 21.2 at mag CV = 14.5. The quiescent counterpart is a 22.5 g mag star, implying an outburst amplitude of ~8 mag. I have just completed the analysis of my unfiltered CCD time-series observations of TCP J08460573+1047397, obtained on 2026 Mar 31/Apr 01 at CBA Belgium Observatory. The data were acquired under mostly clear skies with a 0.40-m f/10.0 telescope and a QHY-268M CMOS camera. I have observed this object on several nights between Mar 21st and Apr 01st but no obvious modulations were seen. However, the Mar 31/Apr 01 light curve clearly shows regular superhump modulations with an amplitude of 0.18 mag. A period analysis using ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.1) yields a combined superhump period of 0.0643 +/- 0.0008d. The object was measured at mag CV = 15.6 on Apr 01st. Image calibration and photometry were carried out using the latest release of Phoranso, which enabled simultaneous photometry of additional variable stars in the same field of view. These results establish TCP J08460573+1047397 as a new SU UMa-type dwarf nova. Further follow-up observations are encouraged to refine the superhump period and study its evolution. I will submit my observations to AAVSO, CBA and VSNET for further analysis. With kind regards, Tonny --- Tonny Vanmunster CBA Belgium Observatory CBA Extremadura Observatory http://www.cbabelgium.co <http://www.cbabelgium.com/> m

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[vsnet-campaign-dn 17576] ASASSN-26bv: new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 23 Mar '26

23 Mar '26

Dear colleagues, ASASSN-26bv was discovered by the ASAS-SN team on 2026 Mar 15.1 at mag g = 17.1. I have just completed the analysis of my unfiltered CCD time-series observations of ASASSN-26bv, obtained on 2026 Mar 22/23 and Mar 23/24 at CBA Extremadura Observatory. The data were acquired under clear skies with a 0.40-m f/5.1 telescope and a Moravian G2-4000 CCD camera. The combined light curve clearly shows regular superhump modulations with an amplitude of 0.45 mag. A period analysis using ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.1) yields a combined superhump period of 0.0565 +/- 0.0003d. The object was measured at mag CV = 16.6 on Mar 24th. Image calibration and photometry were carried out using the latest release of Phoranso, which enabled simultaneous photometry of additional variable stars in the same field of view. These results establish ASASSN-26bv as a new SU UMa-type dwarf nova. Further follow-up observations are encouraged to refine the superhump period and study its evolution. I will submit my observations to AAVSO, CBA and VSNET for further analysis. With kind regards, Tonny --- Tonny Vanmunster CBA Belgium Observatory CBA Extremadura Observatory http://www.cbabelgium.co <http://www.cbabelgium.com/> m

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[vsnet-campaign-dn 17575] TCP J07032576-1241401: updated superhump period
by Yusuke Tampo 16 Mar '26

16 Mar '26

TCP J07032576-1241401: updated superhump period Along with Peter Starr, Josch Hambsh and Itoh-san have reported the time-resolved observations of TCP J07032576-1241401. Using these data, the updated superhump period is 0.06661(1) d, roughly consistent with Peter Starr's previous estimate. ATLAS has detected multiple superoutbursts over the years, with an approximate superoutburst cycle of ~300 days. https://fallingstar-data.com/forcedphot/queue/3994466/ Best regards, Yusuke -- ---------------------------------------------- South African Astronomical Observatory, Postdoc fellow Yusuke TAMPO / 反保雄介 EMAIL: tampo(a)kusastro.kyoto-u.ac.jp ALT. EMAIL: yusuke(a)saao.ac.za ----------------------------------------------

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[vsnet-campaign-dn 17573] TCP J08011102-0343141; new WZ Sge-type dwarf nova
by Yusuke Tampo 23 Feb '26

23 Feb '26

TCP J08011102-0343141; new WZ Sge-type dwarf nova TCP J08011102-0343141 was discovered by the XOSS team on 2026 02 08.8 UT at 15.1 mag. http://www.cbat.eps.harvard.edu/unconf/followups/J08011102-0343141.html Itoh-san has reported the time-resolved observations of TCP J08011102-0343141. The light curve shows double-peaked modulation with a period of ~0.069 d and an amplitude of ~0.02 mag, although 1-d-aliased periods are still possible. Given its large outburst amplitude of ~8 mag, this is most likely early superhumps of a WZ Sge-type dwarf nova. I also obtained an optical spectrum of TCP J08011102-0343141 with the 1.9m telescope at the SAAO Sutherland Observatory on 2026 02 09 UT. The spectrum shows Balmer absorption lines, consistent with this classification. Best regards, Yusuke -- ---------------------------------------------- South African Astronomical Observatory, Postdoc fellow Yusuke TAMPO / 反保雄介 EMAIL: tampo(a)kusastro.kyoto-u.ac.jp ALT. EMAIL: yusuke(a)saao.ac.za ----------------------------------------------

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[vsnet-campaign-dn 17563] Outburst from a WZ Sge-type dwarf nova HV Vir
by Yusuke Tampo 29 Jan '26

29 Jan '26

Outburst from a WZ Sge-type dwarf nova HV Vir Gary Poyner reported a new outburst from a known WZ Sge-type dwarf nova HV Vir, at V=11.964 mag on 2026/01/05 06:59:02 UTC. https://www.aavso.org/LCGv2/static.htm?DateFormat=Julian&RequestedBands=&Gr… Vir&tojd=2461046.180&delimiter=@@@ Time-resolved observations are encouraged. Best regards & Happy new year! Yusuke -- ---------------------------------------------- South African Astronomical Observatory, Postdoc fellow Yusuke TAMPO / 反保雄介 EMAIL: tampo(a)kusastro.kyoto-u.ac.jp ALT. EMAIL: yusuke(a)saao.ac.za ----------------------------------------------

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[vsnet-campaign-dn 17571] TCPJ06571119-1724439: most likely a new WZ Sge-type dwarf nova
by Yusuke Tampo 19 Jan '26

19 Jan '26

TCPJ06571119-1724439: most likely a new WZ Sge-type dwarf nova Yuji Nakamura discovered TCPJ06571119-1724439 on 2026 01 18.5375 UTC at 14.2 mag. http://www.cbat.eps.harvard.edu/unconf/followups/J06571119-1724439.html I have observed TCPJ06571119-1724439 with the Lesedi telescope at the Sutherland observatory on 18 and 19 Jan. The light curve shows double-peaked modulations with a period of ~0.0550 d and an amplitude of ~0.08 mag. Thus TCPJ06571119-1724439 is most likely a new WZ Sge-type dwarf nova. Further observations are encouraged. Best regards, Yusuke -- ---------------------------------------------- South African Astronomical Observatory, Postdoc fellow Yusuke TAMPO / 反保雄介 EMAIL: tampo(a)kusastro.kyoto-u.ac.jp ALT. EMAIL: yusuke(a)saao.ac.za ----------------------------------------------

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[vsnet-campaign-dn 17570] TCP J07353147+0910341: new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 16 Jan '26

16 Jan '26

Dear colleagues, TCP J07353147+0910341 was discovered by XOSS (Xingming Observatory Sky Survey) on 2025 Dec 29.75 at mag 14.8 C. The quiescent counterpart is a 22.4 g mag star, implying an outburst amplitude of ~8 mag. I have just completed the analysis of my unfiltered CCD time-series observations of TCP J07353147+0910341, obtained on 2026 Jan 14/15 at CBA Extremadura Observatory. The data were acquired under clear skies with a 0.40-m f/5.1 telescope and a Moravian G2-4000 CCD camera. I also obtained observations on several nights prior to Jan 14/15, but those did not reveal any obvious modulation. In contrast, the Jan 14/15 light curve clearly shows regular superhump modulations with an amplitude of 0.25 mag. A period analysis using ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.1) yields a combined superhump period of 0.0660 +/- 0.0008d. The object was measured at mag CV = 16.1 on Jan 14th. Image calibration and photometry were carried out using the latest release of Phoranso, which enabled simultaneous photometry of several additional variable stars in the same field of view. These results establish TCP J07353147+0910341 as a new SU UMa-type dwarf nova. Further follow-up observations are strongly encouraged to refine the superhump period and study its evolution. I will submit my observations to AAVSO, CBA and VSNET for further analysis. With kind regards, Tonny --- Tonny Vanmunster CBA Belgium Observatory CBA Extremadura Observatory http://www.cbabelgium.co <http://www.cbabelgium.com/> m PERANSO : The Light Curve and Period Analysis Software http://www.peranso.co <http://www.peranso.com/> m PHORANSO: Photometric Reduction and Analysis Software http://www.phoranso.com <http://www.phoranso.com/>

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